The United States and Japan will step up their defence cooperation to deal with the threat from nuclear-armed North Korea as tensions in East Asia remain high, officials from the two allies said on Thursday.

Flexible work deals fairness tests ignored

More than a quarter of large employers that use individual flexibility arrangements (IFAs) do not check whether their workers are better off.

Opposition Leader Tony Abbott announced on Thursday that the coalition's workplace relations policy would encourage more use of IFAs, which were created by Labor under the Fair Work Act to aid flexibility of working hours and leave.

Under a coalition government, enterprise agreements would not restrict IFAs and the termination period for them would be extended from 28 days to 90 days.

The coalition said it would retain Labor's "better off overall test" to ensure fairness, known as the BOOT test.

A survey commissioned in 2012 by the Fair Work Commission (FWC) found that of companies using multiple IFAs, 27 per cent said they did not conduct a BOOT test.

Of smaller businesses, with just one employee on an IFA, one in five said they did no BOOT test.

Asked how they conducted the BOOT test, only 28 per cent of employers said they compared the employees' wages with the award or Enterprise Bargaining Agreement to see if the worker was benefiting, and 21.5 per cent compared conditions to the award or EBA.